In 1995 -1996, the study mailed a questionnaire to 3.5 million AARP members, aged 50-71 years, who resided in one of six states (California, Florida, Pennsylvania, New Jersey, North Carolina, and Louisiana) or in two metropolitan areas (Atlanta, Georgia and Detroit, Michigan). The questionnaire included a dietary section as well as lifestyle questions. Over 560,000 people returned the questionnaire satisfactorily, making this the largest in-depth study of nutrition and health ever conducted. In 1996-1997, the study mailed participants another questionnaire asking asked more detailed questions about lifestyle and health behavior. In 2004-2006 a follow-up questionnaire was mailed to update the information on selected risk factors and obtain non-cancer outcomes. The participants have been followed through the State Cancer Registry database to identify incident cancers and Social Security Administration Death Master File and National Death Index to identify cause-specific mortality. To maintain contact with the participants, the study have sent an annual newsletter containing the latest research and news about the study.